Soft ice cream is normally dispensed at the point of sale from a soft serve ice cream machine, i.e. a semi-continuous, pressurised scraped surface heat exchanger in which a pre-packaged mix is frozen and aerated. It is typically dispensed at temperatures of −4 to −8° C., for example into a cone, and is then immediately consumed. It is liked by many consumers because of its texture, which is softer than that of ice cream served by scooping from a container kept in a freezer cabinet at around −18° C. Soft serve ice cream machines have a number of disadvantages: they are large and expensive, require training to operate, consume considerable energy, do not deliver consistent product quality if used over a period of time and are inconvenient for the operator to dismantle and clean. Each machine can also only offer one type of product (e.g. flavour/ice cream/sorbet etc) at a time—separate freezer barrels are required for different products.
In recent years, systems for dispensing soft ice cream have been developed in which pre-packaged ice cream is delivered from a container by a dispensing apparatus. U.S. 2006/255066 discloses a dispensing apparatus containing a pressure-displacement device that forces the food (such as soft ice cream) out of its container. The container is located within a chamber which keeps the ice cream at a specified temperature between −6 and −24° C. The chamber is cooled with a compressor refrigeration system that sends refrigerant through the walls of the chamber. A fan may be included with the refrigeration system to help circulate air.
One of the issues inherent to apparatus for dispensing multiple portions of ice cream from a single container is to ensure that the system is hygienic. In particular, whilst it is generally straightforward to keep the frozen confection stored within the dispensing apparatus at a sufficiently low temperature, the nozzle or passage through which the frozen confection flows during dispensing must be open to the outside, at least during the dispensing operation. Therefore there is a potential hygiene issue arising from small amounts of frozen confection being retained within the nozzle and being subjected to higher temperatures, which could result in microbial growth. In U.S. 2006/255066, this problem is in part addressed by making the outlet an integral part of the container which holds the ice cream, so that the valve which controls the flow acts on the outlet portion and does not come into direct contact with the frozen confection. However while this avoids the issue of the contact between the valve and the frozen confection, there still remains the problem of microbial growth on any frozen confection which has remained within the outlet where it is not kept at a low enough temperature.
U.S. Pat. No. 2,950,606 discloses a system for dispensing ice cream having a door hinged to the cabinet which covers the outlet through which the ice cream is dispensed. The door is closed when ice cream is not being dispensed. Cold air is blown through a duct into the region around the outlet through which ice cream is dispensed by a blower. The cold air is said to ensure that the dispensing part of the system is kept free from an accumulation of melted ice cream. However, the outlet still requires cleaning, and moreover the system requires a permanent duct to be provided through which cold air is blown from the main refrigerated body of the apparatus to the outlet.
Thus there remains a need for an improved system for dispensing frozen confections such as soft ice cream.